I've messed around with a few Caddy engines in the past and found if you want the stock intake to flow a bit better you can (see pic) re-work the center divider. With a 1"-2" spacer it will give you a noticeable increase in mid-range power. The better way is of course to purchase the Edelbrock aluminum intake but, plan on speeding $200.00 or more.

"Great" engines with excellent torque!